Engine fuel injectors are expensive because they must be manufactured to operate with high precision and without failure for extended periods of time, at extremely high pressures and vibrations, and across wide temperature ranges. Because of their expense, and for environmental reasons, it is often desirable to remanufacture a used fuel injector rather than to discard the injector and replace it with another one as the used injector approaches the end of its life cycle.
FIG. 1 shows a G2.8 diesel fuel injector 10, with electrical supply leads 20 (usually wires made of copper) extending into the top of the injector 10 to enter “overmold blocks” 30 (usually constructed of molded plastic). The overmold blocks 30 are shown as having a roughly L-shaped profile at the top right-hand and left-hand sides of the injector 10, and each is affixed to an associated stator 35. The electrical leads supply associated stator coils with electric pulses that electromagnetically drive the spool valve 45 from side to side, thereby actuating injection of fuel.
With many types of fuel injectors, a common problem over time is the failure of the electrical leads supplying the stators that actuate the injector's valve(s). Injectors frequently fail because one (or more) electrical lead breaks at the point where it enters the overmold block (or in close proximity to the overmold block), making it difficult to affix a replacement lead in a sturdy manner. In some cases, the lead fails within the overmold block. These failures tend to require that the affected overmold block and its associated stator be replaced on the injector. However, this is time-consuming, difficult, and expensive to accomplish because of the limited availability of stators, the need to replace the wiring within the connection plug, and similar factors.
What is needed is the ability to reliably replace damaged or defective electrical leads within overmold blocks of fuel injectors to extend the life cycle thereof without the need to replace the overmold block and stator of the fuel injector.